Eco-friendly heteropoly acid supported on natural clay for the synthesis of calix[4]resorcinarene derivatives

The catalytic activity of green catalyst heteropoly-11-tungsto-1-vanadophosphoric acid, H4[PVW11O40] (HPV) supported on activated natural clay (HPVAC)  has been tested towards the synthesis of calix[4]resorcinarene under solvent-free condition. It is a one-pot multi-component condensation reaction of four moles of aromatic aldehydes with four moles of resorcinol. The advantages of the protocol, solvent-free heterogeneous reaction condition, simple workup procedure, short reaction time, high yield of products and reusability of the catalyst make this method to declare as green approach for synthesis of calix[4]resorcinarene

Eco-friendly heteropoly acid supported on natural clay for the synthesis of calix[4]resorcinarene derivatives

185-191The catalytic activity of green catalyst heteropoly-11-tungsto-1-vanadophosphoric acid, H4[PVW11O40] (HPV) supported on activated natural clay (HPVAC)  has been tested towards the synthesis of calix[4]resorcinarene under solvent-free condition. It is a one-pot multi-component condensation reaction of four moles of aromatic aldehydes with four moles of resorcinol. The advantages of the protocol, solvent-free heterogeneous reaction condition, simple workup procedure, short reaction time, high yield of products and reusability of the catalyst make this method to declare as green approach for synthesis of calix[4]resorcinarene

Stochastic Numerical Simulation for the Evaluation of Mechanical Properties of Filled Polymer Composites

Reinforced polymeric composites are profoundly used in variety of applications due to its high strength to weight ratio and ease of fabrication. The wide spread application of reinforced polymeric materials in the electronic industries have created a great demand in fabricating a kind of reinforced polymeric system, which is light but has better mechanical strength and good thermal properties. Especially glass microsphere filled epoxy resin composites is used as a potting compound in electronic and aviation industries. Therefore, knowledge of the fundamental thermal and mechanical properties of these systems is highly essential in the formulation of advanced electronic potting compounds. In this work, the effective mechanical properties of glass microsphere filled epoxy system is investigated numerically by stochastic simulation. Numerical simulation software ANSYS is used to characterise the microstructure of the filled epoxy system. MATLAB code has been developed to model the randomness of the particle. The geometric model generated from the MATLAB code is given as an input to ANSYS. Random particle Representative Volume Element (RVE) model is used to evaluate the mechanical properties at various loading fractions. The effect of particle size on mechanical properties of glass microsphere filled epoxy composite is studied. Further the random RVE modeling scheme is compared with single RVE modeling scheme and its significance is reported. The numerically predicted values of effective modulus is then compared with the analytical models and with the literature experimental data. Also the significance of the analytical model on the determination of properties is reported. Then, the effect of interface on the mechanical characterisation by stochastic model is analysed and the debonding of the particle is also simulated

Heteropoly acid supported on activated natural clay-catalyzed synthesis of 3,4-dihydropyrimidinones/thiones through Biginelli reaction under solvent-free conditions

<p>Dihydropyrimidinones/thiones (DHPM’s) have been prepared by one-pot condensation of methyl acetoacetate, aldehydes, urea/thiourea in the presence of heteropoly-11-tungsto-1-vanadophosphoric acid, H₄[PVW₁₁O₄₀] · 32H₂O, (HPV) supported on activated natural clay (HPVAC) under solvent-free reaction condition have been proposed. The DHPM derivatives were identified through elemental analysis and melting point measurements and characterized by FT-IR, ¹H-NMR, ¹³C-NMR spectroscopic methods.</p

Biogenic fabrication of gold nanoparticles using Camellia japonica L. leaf extract and its biological evaluation

Development of green technique for the fabrication of noble metal nanoparticles is of great importance in order to avoid the usage of toxic chemicals. In this strategy, gold nanoparticles (AuNPs) are synthesized at room temperature by using Camellia japonica leaf extract under room temperature. The successful formation of AuNPs was confirmed by various spectroscopic techniques including UV, FTIR, XRD and SEM studies. The resulting antimicrobial activity of the synthesized AuNPs stabilized in C. japonica is tested against seven different microbial strains such as Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. The present study opens a new window for future synthesis of AuNPs via green technique. Keywords: Camellia japonica, Gold nanoparticles, Antimicrobial activity, Green synthesi

Spectral Studies of UV and Solar Photocatalytic Degradation of AZO Dye and Textile Dye Effluents Using Green Synthesized Silver Nanoparticles

The photocatalytic degradation of the chemical dye AZO and dye effluents in different time duration has been investigated using biologically synthesized silver nanoparticles. Dye industry effluents and AZO dye undergo degradation to form harmless intermediate and colourless products following irradiation by UV and solar light in the presence of green synthesized silver nanoparticles. The degree of degradation was tested under the experimental conditions such as PH, temperature, and absorbance of the dye in UV and solar light was measured. The degradation was higher in the UV light source than in the solar light source. Green synthesized silver nanoparticles in the UV light source were found to expedite the dye degradation process

Acinetobacter junii AH4-A Potential Strain for Biohydrogen Production from Dairy Industry Anaerobic Sludge

The present study aims to enhance the efficiency of anaerobic sludge microorganisms to produce hydrogen (H2 ) through various pre-treatment methods. The various pre-treatment methods such as base, acid, chloroform, heat shock, freezing and thawing have enabled to isolate acidogenic bacteria with higher bio H2 producing activity in an anoxic environment. From these various treatments, bacteria were isolated and screened for bio H2 capabilities. Among the one bacterial strain, AH4 strain showed maximum cumulative H2 production and Hydrogen Yield (HY) using 100% diary anaerobic sludge. AH4 strain was identified as Acinetobacter junii using 16S rRNA gene sequence and used for further experimental analysis. Biohydrogen productions of Acinetobacter junii were measured at different experimental setup such as various pH levels (5.0, 5.5, 6.0, 6.5, 7.0, 7.5 and 8.0) and different substrate concentration (10 - 100%) of dairy anaerobic sludge substrate. At pH 7.5 and 60% substrate concentration, the strain AH4 Acinetobacter junii displayed the maximum cumulative H2 production of 945.7 ml/L and H2 yield 1.35 mol H2 / mol glucose. Based on our results, we concluded that Acinetobacter junii can be used as a promising bio agent for hydrogen production on a large scale using dairy anaerobic sludge as substrate

Optimization (Substrate and pH) and Anaerobic Fermentative Hydrogen Production by Various Industrial Wastes Isolates Utilizing Biscuit Industry Waste as Substrate

The bio hydrogen (H2 ) production by anaerobic digestion of industrial waste is beneficial one due to the availability of proteins and carbohydrates as potential substrate for biological H2 production. An anaerobic fermentative route is a promising method of biohydrogenation. The microbial isolates from various industrial wastes (dairy, sugar and food) were assessed for their potential bio H2 production. The selected individual isolates (F1 - Bacillus subtilis and A3 -Bacillus subtilis) and their cocultures were used for the optimization of bio H2 production utilizing various concentration of biscuit industry waste as substrate at various pH conditions. The mixed consortium which displayed the higher bio H2 production was selected for the detailed analysis of the 3L fermentation studies using 90% Organic Loading Rate (OLR) substrate at pH 6.5. Significantly higher Hydrogen Yield (HY) of 0.87 mol H2 /mol glucose on 16th day of incubation was observed